class Student:
    name = None
    age = None
    tel = None
    # 私有成员变量
    __sex = None

    # 构造方法
    def __init__(self, name, age, tel):
        self.name = name
        self.age = age
        self.tel = tel
        print("init success")

    def __int__(self):
        print("init success2")

    def __str__(self):
        print("name,age,tel")
        return f'name={self.name},age={self.age},tel={self.tel}'

    def to_string(self):
        print(self.name, self.age)
